Nicolo and Mira Cassian were the children of Sir Rogerus Cassian, who, alongside his wife, perished in an unfortunate boating accident seven years prior to the events of Falling Kingdoms. Rogerus was a close friend of King Corvin, and so the Auranian monarch took in the orphans, giving them official positions in the palace and allowing them to be brought up with palace educations, alongside Princess Cleo and Princess Emilia. While Mira was lady-in-waiting to Princess Emilia, Nic proved himself to be a useful squire to the king.

Nic was described by Cleo as strange sight in Auranos, with unruly carrot-colored hair and a gawky, sharp angled face, with a nose slightly tilted to the left. His skin was covered in freckles that only intensified the more they were exposed to the sun.